Clamshell bucket



Oct. 20, 1942. E. J. SCHEIB CLAMSHELL BUCKET Filed July 2, 1942 4Sheets-Shee't1 INVENTOR [mew JSC/le/b Oct. 20, 1942. E. J. SCHEIB CLAMSHELL BUCKET Filed July 2, 1942 4 Sheets-Sheet 2 o 9 I E. J. SCHEIB 5 CLAMSHELL BUCKET Filed July 2, 1942 4 Sheets-Sheet 3 55 5.4 I flgg' INVENTOR Oct. 20, 1942. E. J. SCHEIB SLAM-SHELL BUCKET Filed July 2, 1942 4 Sheets-Sheet 4 INVENTOR Patented Got. 20, 1942 UNITED STATES PATENT OFFICE CLAMSHELL BUCKET Elmer J. Scheib, Cabot, Pa., assignor to Blaw- Knox Company, Pittsburgh, Pa., a corporation of New Jersey Claims.

This invention relates to clamshell buckets and, particularly, to a bucket having sheave blocks removably mounted therein adapted for general hoisting purposes when removed.

Clamshell buckets with removable blocks have been known heretofore but have been characterized by several serious objections, the principal one being the amount of time and labor required to remove the blocks from the bucket and replace them therein. Previous buckets provided with removable blocks, furthermore, have used fleet through reeving. Certain difficulties not encountered with removable blocks having fleet through reeving are involved in the removable mounting of blocks in buckets which do not use fleet through reeving but have the usual holding and closing lines secured to dead ends on the bucket.

It is an object of my invention to improve generally on the removable mounting of sheave blocks in clamshell buckets, to facilitate attachment of the blocks to the bucket and their removal therefrom, as well as the attachment of the blocks to and their detachment from a crane boom, when removed from the bucket. To this end, I provide means whereby the blocks are maintained plumb while being removed from the bucket to avoid binding, and means whereby the blocks, on being replaced in the bucket are positively positioned in proper relation to the bucket parts, thus greatly simplifying the operation and making it possible of performance by a single workman. A further object of the invention is to provide connections between the sheave blocks and bucket parts which are stronger than those known heretofore and more easily established and taken down. A still further object is the provision of an easily manipulable connection between the blocks and bucket so arranged that the principal forces involved in the operation of the bucket are applied on the axes of the sheaves and thereby transmitted most directly to the parts associated therewith.

In a preferred embodiment of the invention, I provide a bucket including a head frame, corner bars pivoted to and depending therefrom, cooperating scoops pivoted to the bars and to a hinge casting, with sheave blocks removably mounted in the head frame and hinge casting. The blocks are secured to the head frame and the casting by through pins. The blocks, head frame and casting have cooperating surfaces receive the pins on being lowered into the head frame and hinge casting.

Further novel features and advantages of the invention will become apparent during the following detaild description referring to the accompanying drawings illustrating the preferred embodiment. In the drawings,

Figure l is a side elevation partly broken away showing the bucket in closed position;

Figure 2 is a partial plan View, parts being omitted for the sake of clearness;

Figure 3 is a side elevation showing the sheave blocks apart from the bucket and mounted on a crane boom;

Figure 4 is a view partly in elevation and partly in section along the line IV--IV of Figure 3, with the lower block skewed out of its normal position into parallelism with the upper block;

Figure 5 is a side elevation of the upper block as it is being raised from or lowered into the bucket;

Figure 6 is an end elevation of the upper block;

Figure 7 is a plan view thereof;

Figure 8 is a sectional view showing a portion of Figure 4 to enlarged scale;

Figure 9 is a plan view of the hinge casting receiving the lower block;

Figure 10 is a side elevation thereof;

Figure 11 is a sectional view taken along the plane of line XI-Xl of Figure 9;

Figure 12 is a side elevation of the lower sheave block housing; I

Figure 13 is an end elevation thereof; an

Figure 14 is a plan view thereof.

Referring now in detail to the drawings, a bucket according to my invention indicated generally at Ill, comprises a head frame H having corner bars l2 pivoted thereto and cooperating scoops l3 having corner brackets I4 pivoted to the lower ends of the bars l2, the scoops having extensions l5 pivoted to a hinge casting l6. plates I! connected by cross channels [8. The frame has pivot shafts I9 extending therethrough on which the bars l2 are pivoted. Brackets 20 secured to the bars and extending inwardy thereof are provided with cooperating tooth blocks 2| and 22. Reinforcing ribs 23 extend from the blocks outwardly and downwardly along the brackets 20. The tooth blocks insure that angular movement of the corner bars on one side is accompanied by equal opposite movement of the corner bars on the other whereby the blocks are properly positioned to side. Shelves 24 are Welded on the inner side The head frame II includes spaced side the block 26 has spaced upwardly extending ears 28. A dead-end socket 29 having its lower end bifurcated to fit over one of the ears 28, is secured thereto by a pin 30 removably inserted through aligned holes in the ears and socket. A holding cable 3| has its end secured in the socket 29. The block 26 is also provided, at one side thereof, with a dead-end socket 32 in which one end of a closing cable 33 is secured. The cable 33 is reeved around sheaves in the blocks 26 and 21 and finally passes out of the former between spaced guide rollers 34 journaled on top thereof, up to a sheave in the end of the'boom of the usual traveling crane ordinarily utilized. to handle clamshell buckets.

The block 25 comprises. a generally. box-like housing 35. having spaced side walls. A bearing sleeve 35 extends. through aligned holes in the side walls of the housing and is secured in place by a keeper plate 31: welded to the sleeve at one end thereof. As shown in Figure 5, the keeper plate lies fiat against one of the side walls of the housing and is secured thereto by screws 33. Sheave wheels 39 are journaled on the sleeve 36, as best shown in Figures 4 and 8. The wheels have bearing bushings 40 in the hubs 4| thereof. The rims 42 of the sheaves are connected to the hubs by spokes 43. The hubs 41' are provided with lubricating fittings 44 threaded into angular bores 45' in the hub communicating with oil grooves 46; in the bear ing bushings 44. The side walls of the housing 35 have holes 41 therein whereby a lubricant dispensing device may be applied to the fittings 44. To lubricate the central sheave, the dis pensing device is inserted through one of the holes 4'! and between the spokes of one of the outer sheaves.

The housing 35 has a laterally projecting shoulder 48 adapted to cooperate with one of the shelves 24 to position'the block 25 properly for insertion of a securing pin 49 when the block is being replaced in the head frame. 33 likewise cooperates with the notches 25 to position the block laterally and vertically for ready insertion of the pin 49 which passes through aligned holes in the side plates H of the head frame and through the bearing sleeve 35 as shown in Figures 2 and 8.

The block 21' comprises a housing 50 having spaced side walls within which sheaves 5| are journaled on a bearing sleeve 52 having a keeper plate 53 as shown in Figures 4 and 12, similar to the previously described construction of upper block 26. The side walls of the housing 50 have V rounded recesses 54 in the lower corners thereof for a purpose which will appear shortly. As best seen in Figures 9, 10 and 11, the hinge'casting l6 which removably'receives the block 21 comprises a pair of spaced bearing tubes 55 connected by a horizontal-web or floor 56. At the ends of the casting and above the tubes 45, hollow bumpers 51 are formed being connected to the bearing tubes by vertical webs. Rounded transverse webs 58 extend along the bearing tubes 55 and are adapted to fit into the recesses 5.4 in the housing of the block 21 to position the latter properly for the insertion of its The pin securing pin 59 through the bearing sleeve 52 V and hubs (it formed in the inner ends of the bumpers 5'! and bored to accommodate the pin. The bearing tubes 55 receive pins 6! by which the extensions I5 of the bucket scoops are pivoted to the casting IS. The extensions l5 have shoulders 52 which abut the bumpers 51 on opening of the scoops, thereby limiting the extent of opening.

A shackle 33 extends hrough the horizontal web or floor of the casting l6 and is adapted to be engaged by a crane hook for lifting the bucket when the blocks 25 and 21 have been removed therefrom. It will be understood that the application of lifting force to the shackle will hold the bucket closed while it is being moved.

The sequence of operations involved in removing the blocks from the bucket and replacin them therein will now be explained assuming first that the bucket is wide open and resting on' the ground in stable equilibrium. This means merely that the scoops and their extensions are swung downwardly and outwardly fromthe positions in which they are illustrated in Figure 1 and that the hinge casting i5 and block 2'! occupy lower positions than those illustrated. The first step is the withdrawal of pin 58. This permits the lower block to be lifted out of the hinge casting. This is accomplished by taking. in the closing cable 33. When the lower block has been lifted into engagement with. the upper block further movement of the former is prevented. by contact of their abutting surfaces 64. The pin 33 is then withdrawn from the upper block free.- ing the socket 29. The holdingcable may thereupon be taken in to the desired extent or-may be lashed back out of the way. The closing cable 33 is next pulled over to a position substantially in plumb alignment with the center of gravity of the upper and lower blocks; and secured there by a hook on a chain anchored to the housing of the block 28, as shown in Figures 5, 6 and 7-. Both blocks are then ready for removal from the bucket on withdrawal of pin 49. When the pin is withdrawn theblocks may be lifted by taking up the closing cable. By thus deflecting and holding the cable so as to apply the cable force directly above the center of gravity of the two blocks to be removed, the latter will remain plumb while being lifted, eliminating any tendency to tip and bind or foul in the head frame.

The location of the dead-end socket 32 in the upper block 25, as shown particularly in Figures 1, 3 and 5, is important in order that the operation of lifting out the blocks straight and plumb as just described may be accomplished. Generally in clamishell buckets the closing line socket is placed adjacent the head block, laterally thereof; and substantially at the same elevation as the axis of the sheaves. This applies an eccentric downward force to the upper block equal in magnitude to the cable pull, and in tipping effect to the moment of that force due to its eccentric ity. In my invention, the socket 32 is so located as to direct the cable from the dead-end tangentially to thelower sheave in a line passing through the axis of the upper sheaves when the blocks abut one another as in Figure 3. This eliminates any twisting of the upper block due to the end of the cable being secured thereto in the dead-end socket 32, The location of the socket may be described as below the pin 49 on a line'through the axis thereof and tangent to the'outer sheave 5|. Preferably, the dead-end socket is integrally formed as a recess in the side wall of housing 35, so as to permit close spacing of the cable leads to the lower block (see particularly Figure 6).

When the blocks have been removed from the bucket as described, they may be employed for general hoisting applications using the same hoist and cable reeved therein previously used to operate the bucket, as illustrated in Figures 3 and 4. These figures illustrate the use of the tackle on the boom of the same crane which is used to handle the bucket. The upper block, for example, may be pivoted on a suspension comprising cheek plates 66 hung from the upper end of the crane boom, designated 61, on a through pin 61a. The plates 66 have aligned holes to receive the pin 49 when inserted through the bearing sleeve 36 and holes adapted to receive an auxiliary pin 66'. The side walls of the housing 35 of the block 26 have holes 68 to receive the pin 66' whereby tilting of the block relative to the cheek plates 66 is prevented. As shown in Figures 3 and 4, the closing cable 33 extends over a sheave 61b journaled on pin 61a and serves to actuate the blocks when mounted directly on the crane boom for general hoisting. The holding line is detached and lashed back out of the way.

A crane hook 69 is suspended from the block 2'! by cheek plates 79 through which the pin 59 passes on being inserted through the bearing sleeve 52. By the procedure described, the blocks may easily be removed from the bucket and as easily secured to the crane boom for general hoisting work.

It is not necessary to alter the reeving of the cable 33 over the sheaves of the blocks 26 and 21 in order to utilize the latter for general hoisting work. While Figures 3 and 4 show the abutting surfaces 64 of the blocks in engagement, it will be apparent that this shows the position in which the cable is fully taken up. As the cable is paid out, of course, the block 21 descends, lowering the hook 69, in the manner of the ordinary multiplesheave block and tackle arrangement. It will be understood that the hook 65 is disengaged from the cable when the block 26 has has been secured to the cheek plates 66. Figure 3 illustrates the skew normally existing between the block 21 and the block 26 occasioned by the face that the cable passes from a sheave in one block to a sheave in the other block which would be out of line therewith if there were no skewing.

When it is desired to replace the blocks in the bucket, they are removed from cheek plates 66 and by withdrawing pins 49 and 50. The cable 33 is again engaged by the hook 65 after the blocks have been brought together as illustrated in Figures 3 and 4. The dead-end socket 29is attached to the block 26 by inserting the pin 30. The blocks are then lowered by paying out the cable 33 and cable 31 if necessary. The blocks need only be positioned with their longer dimension in plan generally in line with the length of the head frame. The blocks may be replaced with equal facility regardless of which end thereof is adjacent either end of the head frame. That is to say, the blocks may be replaced in either one of two possible positions, i. e., as illustrated in Figure 2 or with the blocks turned 180 relative to the position of the block 26 as there illustrated.

As the blocks are lowered, the block 21 passes through the head frame. The block 26 likewise descends into the frame until the shoulder 48 engages one of the shelves 24. This positions the block vertically. The pin 30 likewise enters one set of the notches 25 further positioning the block vertically and also laterally so that the bore of the sleeve 36 is in alignment with the holes in the side plate I! whereby the pin 49 may easily be replaced, finally securing the block in the head frame. It will be apparent that the provision of duplicate shelves 24 and slots 25 makes it possible for the block 26 to fit into the head frame as shown in Figure 2 or in the reverse relation with equal facility.

When the block 26 has been secured, the hook 65 is removed from the cable 33 and the latter further paid out to lower the block 21 into the hinge casting l6. It will be apparent that the symmetry of the housing of the block 21 and the recess in the casting I6 which receives the block is such that the block may be received in the casting with one end or the other on a given side of the latter. As already explained, the descending block 21 is arrested by the engagement of the recesses 54 in its side walls with the transverse ribs 58. Upon such engagement, the sleeve 52 is in alignment with the bore through the hubs 60 so that the pin 59 may be readily replaced.

It will be apparent from the foregoing description and explanation that the invention is characterized by numerous advantages over clamshell buckets with removable blocks as constructed heretofore. In the first place, the invention materially reduces the amount of effort and time required for removing or replacing the blocks. Either operation may be performed by one man at the bucket with the cooperation of the craneman. The upper block remains plumb, when being lifted, so that it does not bind in the head frame. While this problem is not encountered in buckets having fleet through reeving since there is no tendency of the upper block to tilt, it has caused considerable difliculty in buckets having one end of the holding and closing lines secured to the upper block. The lower block also remains plumb since it is symmetrical and hangs freely on the bights of the cable.

When replacing the blocks, furthermore, they are arrested at the proper point relative to the head frame and hinge casting, by the engagement of mutually contacting surfaces, so that exact positioning of the blocks by hand is not necessary. The blocks are accurately supported with their bearing sleeves in alignment with the holes in the head frame and hinge casting merely by lowering the blocks until they strike their stops, whereupon insertion of the through pins is but the work of a moment. As previously pointed out, furthermore, the blocks may be seecured with either end toward a given end of the bucket.

The invention also provides removable blocks adapted for easy mounting in separate suspensions carried on a crane boom and for supporting a lifting hook by the same through pins which secure the blocks in the head frame and hinge casting of the bucket. The invention also provides connections between the blocks and the bucket which are simpler, stronger, and easier to make and break, than those previously provided. The construction is such, furthermore, that the forces applied to the blocks are transmitted directly by the through pins to the parts associated therewith.

The dead-end socket for the closing line is so positioned that the force applied to the upper block thereby is in line with the axis of the through pin and thus does not tend to tilt the upper block out of plumb when being lifted from or lowered into the bucket. The holes in the head frame for the through pin are positioned sufficiently below the angle brackets which carry the tooth blocks, to permit removal and insertion of the pin whether the bucket is open or closed. The location of the holes for the through pin in the hinge casting, i. e., in the inner wall of the bumpers, affords ample working room for the insertion and securing of the through pin. The shackle for lifting the bucket when the blocks are removed is in an out of the way position when the blocks are replaced. The provision of lubricating fittings in the sheave hubs greatly facilitates the supply of lubricant as compared with the conventional provisions of axial and radial passages in the sheave pin or shaft.

Although I have illustrated and described but a preferred embodiment of the invention, it will be recognized that changes in the construction and arrangement disclosed may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. Removable sheave blocks for use in a clamshell bucket comprising a head frame, corner bars pivoted to the head frame and depending therefrom,'a pair of bucket scoops pivoted to said corner bars and to a hinge casting below the head frame, said frame and casing having aligned holes to receive pins for securing .the blocks, said blocks including a lower block adapted to pass through said head frame and be seated in said hinge casting, and an upper block adapted to be received in said head frame, securing pins adapted to be removably inserted through said block's, respectively, and said holes in the head frame and casting, and means on said casting and head frame eifective to position said lower and upper'blocks, respectively, for insertionof said pins when said blocks are lowered vertically into the casting and head frame, respectively, said blocks being adapted for general hoisting use when removed from the bucket, and i said pins, to that end, being adapted to be inserted through suspensions associated with a crane boom and hook, respectively.

2. Removable sheave blocks for use in a clamshell bucket comprising a head frame, corner bars pivoted to the head frame and depending therefrom, a pair of bucket scoops pivoted to said corner bars and to a hinge casting below the-head frame, said frame and casting having aligned holes to receive pins for securing the blocks, said blocks including a lower block adapted topass through said head frame and be seated in said hinge casting, and an uppervblock adapted to be received in said head frame, securing pins adapted to be removably inserted through said blocks, respectively, and said holes in the'head frame and casting, said head frame and upper block having interengaging surfaces and said casting and lower block having interengaging surfaces whereby the blocks are properly positioned for the insertion of said pins on being lowered into the head frame and casting, respectively, said pins being adapted to be received in suspensions associated with a crane boom and hook whereby the blocks when removedfrom the bucket may be used forgeneral hoisting.

3. Removable sheave blocks for use in a clamshell bucket comprising a head frame, corner bars pivoted to the head frame and depending therefrom, a pair of bucket scoops pivoted to said corner bars and to a hinge casting .below the head frame, said frame and casting having aligned holes to receive pins for securing the blocks, said blocks including a lower block adapted to pass through said head frame and be seated in said hinge casting, and an upper block adapted to be received in said head frame, securing pins adapted to be removably inserted through said blocks, respectively, and said holes in the head frame and casting, and means on said casting and head frame arresting said blocks, respectively, on being lowered into the casting and :head frame, in proper position for the insertion of said pins through the blocks and said holes in the casting and head frame, said blocks being adapted, when removed from the bucket .to be attached to a crane boom and hook, respectively, for general hoisting.

4. Removable sheave blocks for use in a clamshell bucket comprising a head frame, corner bars pivoted to the head frame, said frame and casting having aligned holes to receive pins for securing the blocks, said blocks including a lower block adapted to pass throughsaid head frame and be seated in said hinge casting, and an upper block adapted to be received in said head'frame, securing pins adapted to be removably inserted through said blocks, respectively, and saidholes in the head frame and casting, said casting having a recess open at the top and said lower block having a downwardly projecting portion'adapted to seat in said recess to position the lower'block' properlyin the casting for insertion of its pin, said pins also serving to secure said blocks removably to suspensions associated with a crane boom and hook, thereby providing hoisting tackle forgeneral use.

5. Removable sheave blocks for use in a clamshell bucket comprising a head frame, corner bars pivoted to the head frame and depending therefrom, a'pair of bucket scoops pivoted tozsaid corner bars and to a hinge casting below the head 'frame, said frame and casting having aligned holes to receive pins for securing the b10cks,'said blocks including a lowerblock adapted to pass through said head frame and be seated insaid hinge casting, and an upper blockadapted to be received in said head frame, securing pins adapted to be removably inserted through said blocks, respectively, and said holes in the head frame and casting, means on; said head frame arresting said upper block on being lowered thereinto, at the proper level for the insertion of its pin and means on the head'frame and upper block effective to position the block laterally for insertion of the pin, said pins being adapted to be received in suspensions associated with a. crane boom and hook whereby the blocks when' removed from the bucket may be used for general hoisting.

6. The apparatus defined by claim '2 characterized by said surfaces being shaped to position'the blocks properly to-rece'ive' the pins, in either of two positions-of the blocks .angularly displaced about the vertical axis of the bucket.

7. Removable sheave blocksfor usezin-a clamshellbucket comprising a head frame, corner bars pivoted to theheadframe and depending therefrom, a pair of bucket scoops pivoted to said corner bars and to a hinge casting below the head frame, said frame and casting having aligned holes to receive: pins for securing the blocks, said blocks including a lower block adapted to pass through said. head frame and'be seatedinsaid hinge ca'sting, and anupper block-adapted to be received in said head frame, securing pins adapted to be removably inserted through said blocks, respectively, and said holes in the head frame and casting, and means on the upper block to lash a cable from the lower block passing over a sheave on the upper block, into substantially a central position relative to the upper block whereby the latter remains plumb when lifted by said run.

8. Removable sheave blocks for use in a clamshell bucket comprising a head frame, corner bars pivoted to the head frame and depending therefrom, a pair of bucket scoops pivoted to said corner bars and to a hinge casting below the head frame, said frame and casting having aligned holes to receive pins for securing the blocks, said blocks including a lower block adapted to pass through said head frame and be seated in said hinge casting, and an upper block adapted to be received in said head frame, securing pins adapted to be removably inserted through said blocks, respectively, and said holes in the head frame and casting, a dead-end socket on said upper block for a cable reeved around sheaves in both blocks, said socket being located so that the force applied thereto by the cable is substantially along a line through the pin of the upper block.

9. Removable sheave blocks for use in a clamshell bucket comprising a head frame, corner bars pivoted to the head frame and depending therefrom, a pair of bucket scoops pivoted to said corner bars and to a hinge casting below the head frame, said frame and casting having aligned holes to receive pins for securing the blocks, said blocks including a lower block adapted to pass through said head frame and be seated in said hinge casting, and an upper block adapted to be received in said head frame, securing pins adapted to be removably inserted through said blocks, respectively, and said holes in the head frame and casting, and means on said casting adapted to be engaged by a crane hook for lifting the bucket when the blocks have been removed.

10. Removable sheave blocks for use in a clamshell bucket comprising a head frame, corner bars pivoted to the head frame and depending therefrom, a pair of bucket scoops pivoted to said corner bars and to a hinge casting below the head frame, said frame and casting having aligned holes to receive pins for securing the blocks, said blocks including a lower block adapted to pass through said head frame and be seated in said hinge casting, and an upper block adapted to be received in said head frame, securing pins adapted to be removably inserted through said blocks, respectively, and said holes in the head frame and casting, sheaves in said blocks having lubricating fittings on their hubs, and holes in said blocks affording access to said fittings.

ELMER J. SCHEIB. 

